1. Technical Field
The present invention relates to adapters for power tools, and more particularly to a right angle adapter with an auxiliary handle that is configured to work with a driving tool and a screwdriver bit.
2. Description of Related Art
For rapid screwing and unscrewing, driving tools (i.e. pneumatic or electric screwdrivers) are often used. However, when such operations have to be performed in narrow space, such as an interval between walls or where an operator may have difficulty in stretching his/her arms, there is a further need for a right angle adapter that facilitates efficient work. Moreover, in order to ensure safe operation and stable use of right angle adapters, they are always equipped with an auxiliary handle.
FIG. 1 schematically shows a conventional handle-equipped right angle adapter, which comprises a main body 11, an adjusting sleeve 12, and an auxiliary handle 13. The main body 11 has its adapting portion 111 provided with a working unit 15 for a screwdriver bit 14 to be inserted therein. A driving portion 112 connected to and driven by the adapting portion 111 has a driving unit 17 for a driving tool 16 to connect and drive, so as to drive the screwdriver bit 14 to rotate in either direction. The adjusting sleeve 12 is rotatably mounted around the main body 11. The auxiliary handle 13 has a grip portion 131 for a user's hand 18 to hold. Furthermore, a positioning portion 132 is connected to the grip portion 131 and comes apart from or presses against the main body 11. By controlling the auxiliary handle 13 to become loose or tight, the adjusting sleeve 12 is allowed to rotate freely or is driven to rotate and then be positioned. In the latter case, the relative angle between the auxiliary handle 13 and the main body 11 varies to adapt to different site requirements, thereby improving working efficiency.
Adjustment of the auxiliary handle 13 involves first unscrewing the auxiliary handle 13, aligning a positioning mark 121 on the adjusting sleeve 12 to a positioning mark 113 on the main body 11, and then screwing the auxiliary handle 13 to make a positioning portion 132 on the auxiliary handle 13 well positioned in a notch (not shown) formed on the main body 11, thereby having the adjusted angle fixed. However, when the positioning mark 121 of the adjusting sleeve 12 and the positioning mark 113 of the main body 11 come to align with each other, there is a lack of a means that preliminarily positions the adjusting sleeve 12 with respect to the main body 11. In other words, the foregoing alignment is unstable. As a result, when screwed to tight, the auxiliary handle 13 may fail to be secured on the main body 11 and bring about an angular offset between the adjusting sleeve 12 and the main body 11. For this reason, the angular adjustment of the conventional auxiliary handle 13 is somehow inconvenient and unreliable.